Background: Besides weight loss Scopinaro's operation produces correction of hypercholesterolemia and noninsulin dependent diabetes mellitus in all patients who suffer from these conditions. These results encouraged us to perform biliopancreatic diversion (BPD) without gastric resection, thus preserving the functions of the stomach and pylorus in moderately overweight patients with hypercholesterolemia associated with diabetes type II and hypertriglyceridemia. Methods: Between March 1996 and July 1997 we performed BPD without gastric resection on 10 moderately overweight patients [mean body mass index (BMI) = 33.2 kg/m2]. All patients had suffered from hypercholesterolemia and hypertriglyceridemia for more than 5 years. Ten patients suffered from diabetes type II; four of them had had insulin treatment or oral anti-diabetic agents; the other patients all had hyperglycaemia in the fasted state and diabetes confirmed by preoperative oral glucose tolerance test (OGTT). Five patients suffered from hypertension. Results: In all patients, cholesterol and triglyceride levels returned to normal within the first postoperative month. Glycemia also stabilized at normal values in nine patients within the early weeks after surgery. One patient who took 70 U of insulin reduced his daily intake to 35 U 2 months postoperatively. In all patients blood pressure returned to normal. Weight loss was predictably slight (10-15 kg). Conclusions: Our experience with the procedure found that this new method seems to be as effective in controlling lipidic metabolism and diabetes II as the original version of BPD. As expected, weight loss is only moderate, so that the modified BPD is not suitable for very obese patients.